Solution-derived 40 µm vertically aligned ZnO nanowire arrays as photoelectrodes in dye-sensitized solar cells

Abstract

Well-aligned ZnO nanowire arrays with a long length of more than 40 microm were prepared successfully by using the polyethylenimine (PEI)-assisted preheating hydrothermal method (PAPHT). Several important synthetic parameters such as PEI content, growth time, preheating time and zinc salt concentration were found to determine the growth of ultralong ZnO nanowire arrays, including length, diameter, density and alignment degree. The photoluminescence (PL) spectrum of as-grown ultralong ZnO nanowire arrays revealed a UV emission and a yellow emission, which was attributed to the absorbed hydroxyl group based on the peak shift after annealing in various atmospheres. The performance of dye-sensitized solar cells (DSSCs) increased with increasing length of ZnO nanowire arrays, which was mainly ascribed to the aggrandized photocurrent and reduced recombination loss according to electrochemical impedance spectroscopy (EIS). A maximum efficiency of 1.3% for a cell with a short-circuit current density (J(sc)) = 4.26 mA cm(2), open-circuit voltage (V(oc)) = 0.69 V and (fill factor) FF = 0.42 was achieved with a length of 40 microm.

Preparation of ZnO Nanorod/Graphene/ZnO Nanorod Epitaxial Double Heterostructure for Piezoelectrical Nanogenerator by Using Preheating Hydrothermal

“…The concentration of zinc nitrate hexahydrate and HMT determines the diameter of ZnO nanorod, the additive PEI would not only provide the enhancement in aspect ratio of ZnO nanorod but also help continuous ZnO growth for long time 17,18 .…”

Research Progress in Preparation and Applications of ZnO Nanowire/rod Arrays by Hydrothermal Method

“…ZnO 纳米线/棒阵列具有长径比高 [6] 、比表面积大 [7] 及电子注入效率高 [8] 等优点, 在发光二极管 [9] 、 纳米发电 机 [10] 、染料敏化太阳能电池 [11] 、紫外探测器 [12] 和气体传 感器 [13] 等领域具有重要应用. 高质量的 ZnO 纳米线/棒 阵列是提高器件性能的决定因素 [10,14] .…”

“…the functional relationship between length of ZnO nanowire arrays and thickness of ZnO seed layer and (c) the functional relationship between length of ZnO nanowire arrays and preheating time [6] 面的粗糙度和结晶质量(图 11b), 进而影响 ZnO 纳米线 的长度和直径(图 11c Figure 15 Side-view SEM image of ZnO nanowire arrays prepared by two-step hydrothermal process [40] 由于制备 ZnO 纳米线阵列时会不断消耗生长液中 的溶质而阻碍纳米线的生长, 所以 2012 年 Chen 等 最近, 本课题组 [48] 首先将 0.0111 g 醋酸锌和 0.0060 g 的氢氧化钠溶解于 12 mL 甲醇溶液中, 超声 2 h 后形 成均匀的种子液; 然后在玻璃基底上旋涂种子液并加热 形成 ZnO 种子层, 再利用微加工技术构建出了微流控 器件(图 17a); 最后在 90 ℃条件下保持生长液的注入速 度为 15 μL/min, 在 6 h 内制备出了长度达到 11 μm 的 ZnO 纳米线阵列(图 17b), 纳米线阵列的制备过程如图 17c. 该方法避免了更新生长液的复杂操作 [11] , 进一步 减少了 ZnO 纳米线阵列的制备时间, 提高了纳米线的 生长效率 [37] .…”

Growth of Ultra-Long ZnO Microtubes Using a Modified Vapor-Solid Setup

“…commonly applied methods to grow 1-D ZnO micro/nanostructures mainly include vapor [17][18][19] and solution-phase approaches [20][21][22][23]. Solution-phase methods have been widely proposed and employed to construct precise morphology due to their low growth temperatures and good potential for scale-up.…”